In a communication system, there is a case where a given node (hereinafter, referred to as “start node”) needs to remote-start a remotely-installed communication node (hereinafter, referred to as “node to be started”) in order for the start node to utilize a function of the node to be started.
A remote start method in a communication system roughly includes two types: one is an inbound system, and the other is an outbound system.
The inbound system is a system in which the start node transmits a start-up signal to the node to be started by using a communication link for data communication. The outbound system is a system in which the start node transmits the start-up signal to the node to be started by using a notification means different from the communication link.
A typical example of the inbound system is WoL (Wake On LAN). In the WoL, the start node transmits a packet having a format called “magic packet” to the node to be started. When detecting the magic packet, the node to be started is turned on and started up. In the WoL, the node to be started needs to always make a network interface in a conduction state in order to detect the magic packet. Therefore, power is consumed even in a standby state before start-up.
In the outbound system, a near field communication used in, e.g., RFID (Radio Frequency IDentification) is used as a start-up signal transmission link different from the communication link. Among the near field communication systems such as RFID, a system called “passive tag system” uses a high-sensitivity rectifier for start-up power control of the node to be started to thereby eliminate the need to consume standby power in a standby state for waiting the start-up signal. More concretely, in the passive tag system, the start-up signal that the start node has transmitted using the near field communication is converted, when being received by the node to be started, into electric power by means of the high-sensitivity rectifier for use in control of initial start-up.